Table III.
Summary of Electrophysiologic Measurements on CFTR Mutants
| Wild type | R347P | R347E | R334W | Mock | ||||||
|---|---|---|---|---|---|---|---|---|---|---|
| ΔGCl (cAMP) (μs) | 121 ± 35 | 125 ± 28 | 5.3 ± 2.1 | 32 ± 20 | −0.61 ± 0.62 | |||||
| (N = 5) | (N = 5) | (N = 5) | (N = 8) | (N = 7) | ||||||
| GBr /GCl | 0.93 ± 0.01 | 1.12 ± 0.01 | 2.36 ± 0.23 | 1.12 ± 0.03 | ||||||
| (N = 5) | (N = 5) | (N = 5) | (N = 8) | − | ||||||
| PBr /PCl | 1.13 ± 0.02 | 1.02 ± 0.01 | 1.00 ± 0.04 | 1.22 ± 0.02 | ||||||
| (N = 5) | (N = 5) | (N = 5) | (N = 8) | − | ||||||
| JATP (Cl) | 8.7 ± 3.4 | 2.0 ± 0.98 | 1.5 ± 0.49 | 3.4 ± 1.3 | 0.021 ± 0.001 | |||||
| (N = 15) | (N = 9) | (N = 11) | (N = 7) | (N = 15) | ||||||
| JATP (Br) | 1.9 ± 0.51 | 0.26 ± 0.17 | 11.0 ± 4.8 | 3.7 ± 1.5 | 0.013 ± 0.006 | |||||
| (N = 15) | (N = 9) | (N = 11) | (N = 7) | (N = 15) | ||||||
| JATP (Br)/JATP (Cl) | 0.22 | 0.13 | 7.3 | 1.1 | − |
CFTR cRNAs were injected into Xenopus oocytes and evaluated for both electrophysiologic and ATP release characteristics. ΔGCl (cAMP), change in Cl− conductance in response to IBMX/forskolin; GBr/GCl, halide conductance ratio; PBr/PCl, halide permeability ratio, JATP (Cl), rate of ATP efflux in the presence of extracellular Cl− (pmoles ATP/min); JATP (Br), rate of ATP efflux in the presence of extracellular Br− (pmoles ATP/min); JATP (Br)/JATP (Cl), halide dependence ratio of ATP efflux. Values represent the Mean ± SEM with N = number of oocytes analyzed from two to three independent frogs.